Sofa



FIG. 1 is a front, right-side, top perspective view of a sofa, showing the new design;

FIG. 2 is a front perspective view thereof;

FIG. 3 is a right-side perspective view thereof, the left-side perspective view being a mirror image thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a front perspective view thereof with a backrest extended. 

CLAIM The ornamental design for a sofa, as shown and described. 